package com.xiaoye.digitaltwin.config;

import com.xiaoye.digitaltwin.common.JacksonObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;

import java.util.List;

/**
 * Create by xiaoye on 2023/3/24
 */
@Slf4j
@Configuration
public class WebMvcConfig extends WebMvcConfigurationSupport {
    /**
     * 扩展消息转换器  将Controller返回的结果转成相应的JSON
     * Long型id转换为String字符串，避免前端精度丢失
     * @param converters
     */
    @Override
    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        log.info("消息转换器启动");

        //创建消息转换器对象
        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();

        //设置对象转换器，底层使用Jackson将Java对象转为json
        messageConverter.setObjectMapper(new JacksonObjectMapper());

        //将上面的消息转换器对象追加到mvc框架的转换器集合中
        converters.add(0,messageConverter);
    }
}
